The first farmers who swept into Europe 6000 to 7000 years ago may have grown too big for their britches—or animal skins—too fast. A new study of archaeological sites across Western Europe highlights a strikingly consistent pattern in Neolithic farmers' communities: Their populations grew too big, too quickly, and crashed right after they peaked.

"We can see a dramatic history of booms and busts," archaeologist Stephen Shennan of University College London (UCL) reported yesterday in a talk at the 111th meeting of the American Anthropological Association in San Francisco, California.